Brake-operating mechanism



y L. BOIRAULT.

BRAKE OPERATING MECHANISM.

HLED APB.12.1920. 2 sHEETssHEsTl.

Feb. 13', 1923; 1,445,065.

l 1o 25 42V i2 i5 Feb. 13, 192s. 1,445,065.

L. BOIRAULT.. BRAKE OPERATING MECHANISM.

FILED APR. I2 1920.

. 2 SHEETS-SHEET 2- 7 oscillates under the combined action oit pulls onthe rod S and produces the desired application ot the brakes by the aidoit one or more springs interposed in the rigging. This application oit-he brakes is Vthe more energetic the more the cam 4L lis rotated in a-forward direction and the more4 the portionlll to l5 lifts the arm 16upward.

In orde-r to prevent the reaction ot thc brakes which create apowertulpressure ot' the arm i6 on the cam 4:, from producing` the recoilofthisv latter in the reverse direc tion oi' the arrow D,notwithstanding the slight inclination ot the portion la to l5, thepresent apparatus has a catch arrangement ot the ratchet type.

This arrangement has two pawls 2() and `tions which differ from eachother by only half the pitchy ofthe series oi teeth. ln consequence otthe large diameter ot the ring', the angular distance apart correspomling to these successive positions may be relatively small. y

ln the position of rest shown, the pawls -are held away from the ring bythe pressure of suitable parts or' the flywheel on thel tails 2Oa and21a of the pawls. A s soon as the flywheel is moved in the direction ol:

' the arrow D relatively to the cam, .the pawls are left to the actionot the springs 2li and bear against the ring, so that they opposethemselves to the recoil. ol the cam as longl as the flywheel is notbrougght back to the rear.

A cam 26 the proiile of which maybe similar to that of the cam 4 ismounted, like this latter, on the hub of a second iiXed plate 39a,through which the' shaft 9 likewise passes. This cam, whichv is intendedto hold. the brakes on after they have been ap plied, is arrangedopposite the elbow lever' 6, 7; the proiilevoi which is determined insuch a way that the profile of the carri 26 trayels over it inproportion as the lever 6,

the cam e and the eccentric 2. A compensat ing elastic driving memberfixed to the le ver 7 communicates' the movement ot thisV lever to thecam 26. This member comprises a shaft 28 mounted on the arm 7 so as tobe capable of rotatingand provided with' tached at one end to the rod 30and at thc other end to a pin 35 attached to the cam 26, this chainpassing around the hub of this latter. he diameter oli this hub is suchthat the driving oi the cam 26 by the chain 34e leaves the prolile otthis cam :lightly and progressively '\ehind the protile of the lever 7during the movement which puts the brakes on. y rlhis retardation iscompensated by the progressive expansion of the spring 32.V lt resultsfrom thisarrangement that on the reverse morement (the taking' oli' otthe brakes) the spring 32 is compressed progressivfely and o'dersarcsistance to the untimely return backwards of? the cam 26 under theeiect ot the reyersibility which is always to be feared in consequenceoit shocks.

rlhe keeping on of the brakes is completed by a set of pawls 36 and 37,similar to the pawls 20, 2l of theV cam 4. These pawls, which aremounted on the cam 26, bear 'likewise against the toothed ring` 2,5.

To take the brakes oil, it suitices to rotate the shaft 9 in the reversedirection to the arrow D. 'lfhe first rotary movement of the iiywheel l0has the eilect oit causing the pawls 20, 2l., 36, 37 to oscillate so asto disengage them from the ring 25. rll`hen the flywheel drives roundthe cam 4l by the aid of the pin l2 or the tail 20a ot the pawl 20, andthe cam 26 by the aid oit the tail oi? the pawl 36. y

In the constructional 'form shown, the shaft 9, the spindle 19 on which`the lever 6, 7 oscillates, and the spindle 17 ot the arm 16 are carriedby the two plates 39, 39a. rlhese latter are fixed to cross bars l0forming a support which is itsel't vfixed to the frame of the vehicle.These plates are connected together bythe spindle 17 and by two boltsll, which likewise pass through the ring 25, tiis latter being` held inplace by tubes 42 which form cross ties. l y y The whole of theapparatus will be pref-` erably enclosed in a casing containing somelubricating` material, the use thereof being rendered possible by theslight inclination of the portion 14 to l5 and by the catches, and

having the advantage of ensuring the ,constancy oi the co-etlicient oftrictien between the cam and the parts against which they actl 4lt is tobe understood that by reason of the slight inclination-oi' the `camsurfaces with regard to the radii, it is possible to obtain a perfecteitect of wedeging, even it the slidingl coeiicient between thesesurfaces is feeble, i. e., it they are lubricated.V lt is 0bvious thatthe iriction coetlicient of constantly lubricated surfaces willremainalways invariable, especially it the cams are enclosed in a casingfilled with oil, while with cams working` in the yatmosphere. and notlubricated, the rust cinder, snow, ice,

eta, will to a greatdeal modify Ithe friction coetlicient. It istherefore advantageous from the standpoint of the security of theworking` to lubricate the cams and to preserve them from the prejudicialaction coming from the outside.

Claims:

l. An operating device for brakes coniprising t-he combination of aneccentric iiXed on an axle, a brake rigging rod, a lever connectedoperatively to this rod, a rotatable cani adapted to operate the saidlever in order to bring it into the path traversed by the saideccentric, retaining pawls mounted on the said cam and a fixed toothedring with which the said pawls co-operate in order to prevent therotation oiE the said cam under the influence ot the reaction of thesaid lever.

2. An operating device Afor brakes comprising the combination of aneccentric iXed on an axle, a brake rigging rod, a lever con nectedoperatively to thisrod, a rotatable cam adapted to operate the saidlever in order to bring it into the path traversed by the saideccentric, a rotatable operating plate connected to the said cam by alost motion connection, retaining pawls mounted on the said cam and afixed toothed ring with which the said pawls cooperate in order toprevent the rotation of the said cam under the ininence of the reactionof the said lever, the said plate having projections adapted to engagethe pawls and move them away from the said toothed ring when it isrotated relatively to the cam in the ydirection corresponding to thetaking' oli' of the brakes.

3. An operating device for brakes comprising the combination of aneccentric fixed on an axle, a brake rigging rod, an elbow lever havingone arm connected to said rod, a second lever pivoted to the other armoi the said elbow lever, a rotatable can-'1 adapted to operate thesecond lever in order to bring it into the path traversedby the saideccentric, a second cani` adapted to be actuated by the [irst mentionedcam, and anelastic connection between the said elbo-w lever and l thissecond cam, the periphery of this latter cani being adapted to engagethe said elbow lever and serving' to prevent any undesirable looseningof theibrakes.

t. An operating device for bralsl com prising the combination of aneccentric fixedv tween the said elbow lever and this second l cam, theperiphery of this latter cam being adapted to engage the said elbowlever and serving' to prevent any undesirable loosening ot thebrakes, aliXed toothed ring and 're-v taining' pawls mounted on said cams andadapted tocooperate vwith the said toothedi ring.

ln testimony, that I claim the foregoing as my invention l liave" signedmy name in presence o'f two subscribing witnesses.

LOUIS BOIRAULT. Witnesses HENRY T. WILooX,

MAURICE ROUX.

